Dyeing of Polyester Fabrics with Indigo

Abstract

Polyester fabric was dyed with indigo through the exhaust technique by controlling the ratios of sodium dithionite and sodium hydroxide concentrations in the dyebath solution. At different ratios different forms of the indigo existed and each one had different degrees of substantivity for the polyester. The non-ionic form such as disperse dyes, had substantivity for polyester. Polyester could best be dyed in the acidic to slightly neutral pH range. The reflection spectra showed that the absorption maximum for polyester was at 610 nm. Rubbing and washing fastness were better while light and sublimation fastness were poor.